โ Scribed by Hassan Ghanem; Dan Zollinger; Robert Lytton
No coin nor oath required. For personal study only.
Alkali-silica reaction has become in concrete structures a growing and annoying problem for engineers, contractors and government agencies. Laboratory standards tests like ASTM C 1260 and ASTM C 1293 are available and are currently used by researchers and agencies. However, those tests have limitations and drawbacks. Those short comings warrant a completely different approach to ASR testing. Hence, a detailed study was conducted to develop a reliable aggregate test protocol that will assist the engineers, contractors and owners to identify and measure the potential for concrete pavement degradation because of ASR. Results indicate that the activation energy concept of ASR can be seen as a useful parameter and has the potential of playing the role of a screening parameter for rocks with different reactivity. Statistical analysis conducted shows that the test protocol is highly repeatable and reliable.
๐ SIMILAR VOLUMES
The cycloaddition reaction between C,N-diphenyl nitrone and an unsymmetrically disubstituted olefin, methyl crotonate has been studied in terms of several theoretical approaches at DFT/B3LYP/6-31G(d) level of theory. The electronic populations have been computed from natural orbital based charges us